/Engine/Plugins/Experimental/TextToSpeech/Source/TextToSpeech/Public/TextToSpeechEngineSubsystem.h
Immediately stops any currently vocalized string on the channel. If the provided channel Id does not exist, nothing will happen.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category=TextToSpeech) void StopSpeakingOnChannel ( [FName](API\Runtime\Core\UObject\FName) InChannelId )